A variety of processes have been proposed for the surface treatment of plastic substrates. These include, for example, corona treatment, cold gas plasma surface treatment, and other chemical treatments. Several U.S. patents illustrate known surface treatment processes.
U.S. Pat. No. 4,046,706, issued to Krezanoski, discloses cleaning a contact lens in a cleaning solution comprising specific surfactants to reduce the contact angle of the lens surface.
U.S. Pat. No. 4,063,890, issued to Barron, discloses asceptization of a contact lens by exposing the contact lens enveloped in a saline solution to UV radiation having wavelengths longer than 221 nm in the substantially complete absence of ozone.
U.S. Pat. No. 4,104,187, issued to Sibley et al. discloses, discloses disinfecting soft contact lenses at an elevated temperature in an aqueous saline solution containing specific surfactants.
U.S. Pat. No. 4,214,014, issued to Hofer et discloses, discloses a surface treatment for hard or dehydrated hydrophilic contact lenses in an oxygen gas plasma at low pressures, preferably equal to or less than 10 mm Hg.
U.S. Pat. No. 4,229,273, issued to Wajs, discloses grafting an unsaturated monomer to a silicon resin contact lens by irradiating the molded silicon resin contact lens with non-ionizing UV radiation having a wavelength within the range of 1800 to 4000 Angstroms and a power intensity of 100 to 1000 mWatts/cm.sup.2 for 5 seconds to 30 minutes in the presence of oxygen and subsequently contacting the contact lens with a specific monomer.
U.S. Pat. No. 4,552,626, issued to Stevenson, discloses the cleaning of plastic substrates with an alkaline cleaning solution and deglazing resin from the surface with an acid or organic solvent prior to electroplating the plastic substrate.